Democratic lawmakers say Deutsche Bank should “simply ask” US President Donald Trump for authority to comply with a House of Representatives committee’s request for documents relating to his and his family’s business dealings.

Mr Trump’s relationship with Deutsche is of interest because he has at least $130m in loans from the bank to fund his organization’s hotel and golf properties, according to the president’s recently-released financial disclosure records.

“Given President Trump’s repeated assertions that he does not have ties to Russia, such disclosure would ostensibly be in his interest,” said the letter dated Wednesday, which was signed by Maxine Waters, the ranking member of the House Financial Services Committee and four other lawmakers. The committee made its initial request last month.

Deutsche has refused to turn over documents pertaining to loans granted to Mr Trump, citing federal customer privacy laws. Deutsche also said federal law prohibited it from complying with requests for information about the bank’s internal review into an alleged “mirror trading” scheme that authorities allege was used to launder $10bn out of Russia.

On Thursday, a Deutsche Bank representative referred to its June 8 letter addressed to the committee: “We hope that you will understand Deutsche Bank’s need to respect the boundaries that Congress and the courts have set in an effort to protect confidential information.”

In the latest letter the lawmakers said, “We respectfully disagree with your interpretation of the law’s application to our inquiry, and therefore reiterate our request for the information enumerated in our original letter.”

Lawmakers have said they are “in the dark” on whether loans extended by Deutsche to Mr Trump were guaranteed or connected to the Russian government.

Those ties also raise potential conflict of interest concerns, lawmakers have said. Deutsche is under investigation by the US Department of Justice in connection to the “mirror trading” scheme. Earlier this year Deutsche agreed to pay $630m to settle related UK and US regulatory allegations.

The House committee doesn’t have legal authority to compel Deutsche to comply but has asked the bank to respond by June 29 .

The bank said in a statement on Thursday:

“We reiterate that while we seek to cooperate, we must obey the law. Our lawyers will respond to the legal questions raised by the individual members of Congress in due course. In the meantime, we continue to refer the members to the legal basis from our previous response.”